Sensor device for a motor vehicle system

ABSTRACT

The invention involves a sensor device for a vehicle control system, comprisig -a buffer for geographic information, whereby the geographic information is suitable to describe at least one possible route of the vehicle, -an input interface to select subsets of the geographic information stored in the buffer, whereby the selection is effected by the provision of at least one position-related parameter at the input interface, -an output interface to select subsets of the geographic information corresponding to the parameter values provided, whereby the output information is sent for further processing in the vehicle control system.

BACKGROUND AND SUMMARY OF THE INVENTION

This application claims the priority of German patent document 102 44329.7, filed Sep. 23, 2002 (PCT International Application No.PCT/EP2003/09721), the disclosure of which is expressly incorporated byreference herein.

This invention relates to a sensor arrangement device for a vehiclecontrol system. A sensor is an electronic component which convertsquantifiable values into electric signals, reporting them for additionalcomputer-assisted processing.

Modern vehicles have a variety of sensors, which in some cases areincorporated in the vehicle and support the driver in criticalsituations, increase driving comfort, or reduce fuel consumption andenvironmental pollution. A system to increase driving comfort may be aradar-supported, automatic headway control. An example of a method toreduce fuel consumption is a gear change-adapted system, i.e., optimalautomatic gear changing for minimal fuel consumption.

While such systems function reliably in normal situations, difficultiesmay appear under certain circumstances. Thus, with radar-supportedautomatic headway controls problems may arise in curves or with objectslike bridge piers if the radar signal is only available to interpret oneobject configuration. With the gear change-adapted method only actualvalues are available, such as an instantaneous turning moment, to derivea moment value for a gradient or an instantaneous steering angledeflection to derive a moment value of the curve. Therefore, a“projection” of future values, and thus an estimate of a futureevolution, are not possible.

The availability of geographical information stored in digital road mapsrepresents an opportunity of providing vehicle control systems withadditional, more versatile, information. For example, German patentdocument DE 37 00 552 A1 discloses a vehicle-based navigation system,which includes a digital road map and additional vital information thatis used upon reaching the assigned geographical position and/or is toused control systems in the vehicle. By outputting the informationand/or controlling the system in the vehicle, automatically collecteddriving and environmental information, like speed, can be considered.

European patent document EP 1 111 336 A1 describes a procedure for theuniversal application of a digital roadmap, in which routes are storedin the digital roadmap in the form of edges and nodes to control thevehicle. Beginning at a current location of the vehicle, variouspossible routes are calculated. In the process an “electronic horizon”is created whose extension is dependent on the type of each route ahead.The geographic information assigned to each route within the electronichorizon is stored in a buffer. The geographic information stored in thedigital road map may vary in accuracy for different vehicle controlsystems, and is correspondingly identified. The information stored in abuffer is supplied to the vehicle control system by a broadcastmechanism (transmission via a vehicle-based network). Each system isconfigured in such a way that it only receives the information requiredby the vehicle.

The use of geographic information stored in a digital roadmap, however,entails several disadvantages. On the one hand, digital roadmaps aredesigned and optimized especially for vehicle navigation. In the presentcase, navigation is not the main reason for using the digital roadmap;rather, it performs a “storage function” for geographic informationwhich is used to operate vehicle control systems. The digital road mapincludes much information that is not needed in this field ofapplication. (Reference is made here to FIG. 1.) If only geographicinformation to operate the vehicle control systems is called for,unnecessarily expensive storage space is used, which in turn requiresthe installation of expensive devices in the vehicle for such an amountof data, e.g., a CD ROM or DVD player. The information actually requiredcould be stored in an economical memory chip instead. In addition, anexpensive, vehicle-based navigation system must be incorporated tooperate the digital roadmap, even in cases where such navigation systemis actually not needed, e.g., if the vehicle uses a centrally-basednavigation system.

In addition, as shown in European patent document EP 1 111 336 A1, forinstance, extensive and complicated configuration, and transmission andreception operations are necessary to make the geographic informationavailable to the vehicle control systems. The reason is the “universal”use the same digital roadmap for different vehicle control systems. Onthe one hand, this increases both the volume of data traffic in thevehicle's internal network (e.g., the CAN—“Controlled Area Network”),and the complexity of the corresponding system structure. On the otherhand, it is also fault-prone, not allowing for a separation betweencomfort functions and safety critical functions, so that the geographicinformation provided turns out to be unreliable for use in vehiclecontrol systems.

One object of the present invention, therefore, is to provide a vehiclecontrol system with required geographic information in an easy, economicand stable manner.

This and other objects and advantages are achieved by the sensorarrangement according to the invention, in which a storage buffer isprovided for geographic information that is suitable for describing oneor more vehicle routes. An input interface is provided for selecting asubset of the geographic information stored in the buffer, suchselection being activated by providing at least one parameter value atthe input interface. An output interface outputs the subsets ofgeographic information corresponding to provided parameter values, andthe latter are sent for further processing in the vehicle. In otherwords, neither a digital roadmap nor a “navigable” (suitable for vehiclenavigation) data set is required. Not even a navigation system tocontrol the digital roadmap is required.

According to this invention only a geographic information buffer cacheis provided. The buffer stores geographic information suitable todescribe at least one possible route, which wholly or partiallycorresponds to a route from a starting to an arrival point. Thisprocedure offers several advantages: For the first time, a completeseparation between geographic information provided for use in vehiclecontrol systems and geographic information used for navigation has beenimplemented. This is an important advantage in safety critical vehicles,for instance.

In a further embodiment of the invention, the geographic informationused by safety critical vehicle control system can be certified, (i.e.,it is specially checked by state agencies or other trustworthyinstitutions). In contrast, commercially available digital roadmap isnot certified, nor could it possibly be, due to the huge amount of datait contains. A mixture of certified and uncertified information, whichwould be questionable from the safety point of view, is effectivelyprevented by the invention-related isolated buffer cache for certifiedgeographic information used by safety critical vehicle control systems.

A further advantage of the separation between the geographic informationintended for use in vehicle control systems and the geographicinformation used for navigation, is the independence which it gives thevehicle manufacturer from navigation systems producers. Navigationssystems, as electronic consumer goods, are subject to a quick productioncycle and constant advancements. Thus, with every new generation ofnavigation systems used in vehicles, new adaptations are required,(e.g., of the interfaces and of checks and functional tests, especiallywith safety critical vehicle control systems). Such advancements innavigation systems, however, involve only the navigation function, asthe provision of geographic information for vehicle control systems isall but a “secondary task” of a navigation system. The input and outputinterfaces of the invention-related sensor device, which constantlyremain the same, represent significant cost and labor savings.

Another advantage of the invention in particular consists of its use incommercial vehicles, which usually drive along only one or a few routes,so that a comprehensive digital roadmap is unnecessary. In addition,commercial vehicles usually do not use a vehicle-based navigationsystem, since the drivers generally know the few routes to be drivenalong very well, and centrally based navigation and management systemsare frequently used, e.g., “Fleetboard”™ by the DaimlerChrysler Company.Due to the cost pressure in the transport business, vehicle-basednavigation systems have had to be dispensed with, and no geographicinformation could be used in the vehicle control system. This inventionremedies that problem.

Commercial vehicles in particular usually have other control devices.For example, in addition to the centrally based navigation andmanagement system already in use, in the near future it will becompulsory to outfit heavy commercial vehicles with a device tocalculate the road impact fee, which will require a calculator andadditional sensors incorporated in the invention-related buffer. Thesensors are especially for positioning, e.g., with GPS (“GlobalPositioning System”), and additional sensors are used for monitoring andcorrecting of positioning errors, (e.g., in an odometer or an electronicgyroscope). Furthermore, devices to communicate with external units areprovided by means of GSM (“Global System for Mobile Communications”) orDSRC (“Dedicated Short Range Communication” short range communications),for instance. Actually, positioning itself is carried out through thesedevices.

In a further embodiment these devices are advantageously assembled in asingle packaged circuit. Thus, at least some of the additional sensors,the calculator and the invention-related sensor device form a compact,are standardized and therefore low cost telematics platform. In additionto the invention-related sensor device the platform comprises thein-vehicle component of a centrally based navigation and managementsystem and/or the road impact fee calculator.

According to this invention, one or more position-related parametervalues are provided at the input interface of the buffer to select asubset of the stored geographic information. Further advantageousadvancements allow for other parameter combinations in addition to thecurrent position of the vehicle. In particular these are partialsections of the current route or geographic area, provided by acentrally based navigation system. A geographic area is formed by a“funnel” opening around the. current vehicle position, whose sizedepends on the vehicle speed and whose opening angle depends on thevehicle direction. Here a variety of possibilities exists depending, inparticular, on the type of the vehicle control system. The connection ofthe input or output interface of the buffer to the vehicle-based datanetwork (e.g., CAN—“Controlled Area Network”) is thereby advantageous.This way, an especially easy transmission of the required additionalsensor values and/or geographic information is possible.

Alternatively, an additional calculator (e.g., a vehicle computer orcontrol device) can be provided in the vehicle to control theinvention-related sensor arrangement, so that the sensor arrangement hasits own calculator to determine the position-related parameter values,The incorporated calculator can directly process additional sensor data,and thus determine the position independently. In another embodiment theincorporated calculator selects the next partial section of a routedetermined by a centrally based navigation system. Here a variety ofembodiments is possible. Naturally the calculator and the sensor devicecan be designed as a single structural unit. In addition, a sensordevice can be assigned to each vehicle control system. Alternatively onesensor device can be used by several vehicle control systems. In theprocess one or more incorporated calculators can again be provided. Anysuch combinations are thereby possible.

Advantageously, the invention-related sensor arrangement is designed asan “intelligent” sensor, especially easy use based on the “plug & play”(self-configuration without additional adaptation) principle.

According to the invention, the geographic information stored in thebuffer is not all-purpose information for navigation, for the vehiclecontrol systems operations or for other purposes; rather it is providedespecially for the operation of one or more vehicle control systems,instead. Thereby a significant reduction of the extent of the requireddata results, as there is no need for the data to be suitable fornavigation.

In an especially advantageous embodiment, the storage format used forthe geographic information stored in the buffer is a type which requiresvery little storage space and, in particular, is highly accurate. Sinceit is not suited for navigation, such a data format has not been usedpreviously for storage of geographic information in a vehicle. Thisinnovative data format basically turns away from the usual reproductionof sections of a digital roadmap using edges and nodes. Especially fornonlinear route sections, like curves, the latter type of reproductionis inaccurate and requires a great deal of storage space, because curvesusually have the form of circular arcs or the form of a clothoid (Comuspiral). Clothoids, or even curves whose curvature increasesproportionally with the arc length, are used as a transition betweencircular arcs and straight sections or between two circular arcs. Bymeans of a parameter-based description of non-straight route sections asa circular arc or a clothoid or a spline, enormous storage space issaved, since only the corresponding parameters need be stored. At thesame time, the accuracy of the geographic information is significantlyincreased, since no fault-prone “approximate solution” in the form of anapproximation with edges and nodes is stored. Instead the exactreproduction is stored in the buffer. In addition, the access to thegeographic information is accelerated and the assigned processing unitis relieved of calculating tasks.

According to the invention, only one or a few routes for the vehiclewill be stored in the buffer. As already shown, this arrangement isespecially advantageous in commercial vehicles. But from time to time itis necessary to provide new geographic information, not stored in thebuffer theretofore, for example when completely new sections or routesare to be provided to the vehicle control systems. The same is also truewhen changes have been made to the stored routes and due to road worksor construction. These changes are made in an especially easy way, ifthe buffer can be overwritten. It is advantageous, if the geographicinformation is partially or incrementally or completely changeable andthe various changes can be easily made. Naturally, these possibilitiesare based on the calculation code stored in the incorporated calculatorpotentially associated with the sensor device.

In another especially advantageous embodiment the buffer is designed asa flash ROM. Changes can thus be made comfortably without the risk oferroneously deleting the geographic information. The change is made bymeans of a data line connected to the buffer, which is accessible via anappropriate interface. In a further embodiment the buffer is designed asa mobile ram which is easily inserted by the vehicle driver into abracket and so made accessible to EDP.

Because certified geographic information is relatively expensive toproduce and to acquire, the use of large amounts of data, (e.g., adigital roadmap), is hardly promising. On the other hand, such amechanism is ideally supported by an overwritable buffer, as only one ora few routes are stored. It thus involves only moderate costs to keep upwith the state of the art. This way, a reliable vehicle control systemfurnished with geographic information is always guaranteed.

The vehicles furnished with geographic information by theinvention-related sensor are basically best operated on highways. Inbuilt-up areas, the traffic flow is basically influenced by the vehiclesdynamics due to traffic lights and intersections and thus a reasonableuse of the of the system in the vehicle is impeded. Therefore onlycountryside-related geographic information is advantageously stored inthe buffer.

Numerous vehicle control systems benefit from being furnished withgeographic information systems. On the one hand, the functions ofalready existing systems (for example radar-supported, automatic headwaycontrol) are further improved and can still be more versatile. In theprocess of evaluating an object configuration, further information, inaddition to the radar signal, is provided by the detection of an objectahead using the geographic information. This considerably increases thecertainty of detection in difficult situations such as, for example, incurves or with bridge piers. With gear change-adaptation, the geographicinformation is now available in addition to the current values, as ananticipation of future values (for example, an instantaneous turningmoment to derive a moment value for the gradient, or an instantaneoussteering angle deflection to derive a moment value of the curve). Thusvehicle situations can be better estimated. For example, it is nowpossible to check, whether a gradient limit value was exceeded for ashort time or whether a longer gradient section actually lies ahead.

On the other hand, supplying the invention-related sensor device withgeographic information facilitates the design of totally innovativesystems. A particular highlight here is an anticipated curve warning.Especially with commercial vehicles tip-over accidents with severeconsequences repeatedly occur even with experienced drivers onfrequently traveled routes. The invention-related sensor arrangement isideally suited to significantly reduce the number of such accidents.Further examples of innovative vehicle control systems are a curvelight, (i.e., a forward looking deflection of the headlights dependingon the road curve), a warning of upcoming locations where the vehiclecannot pass, like bridges or narrow spots, a situation-adapted warningand information management, so as not to overload the driver withstimuli, and a predicative diagnosis with actual, local load complexesacting on a component.

Other objects advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph which illustrates requirements for individual types ofinformation with a commercial digital roadmap; and

FIG. 2 a) and b) are graphs which illustrate requirements for individualtypes of areas with a commercial digital roadmap; and

FIG. 3 a) to c) show each preferred embodiments of the invention.

In FIG. 1 the storage requirements for individual types of data with acommercial digital roadmap are shown as a pie chart. Especially depictedhere is the storage requirement of a digital roadmap in the form of aCD-ROM for Germany by the NavTech Company. In the following sectionvarious types of data stored according to the state of the art will beexplained briefly.

Addresses, e.g., street names and house numbers, are the geographicinformation used as the starting and arrival points in navigation.Restrictions relate to unauthorized crossing at intersections, (e.g.,turning prohibitions). Attributes are associated data providingadditional information, for example, number of lanes on a road, whilegeometry relates to the geographic representation of the distance withedges and nodes. Topology, on the other hand, is the logicalinterconnection of distances and nodes. Polygons relate to informationto be visualized during navigation, e.g. the boundaries of woodland orcities; and POI relates to points of interest which can be used asstarting, arrival or intermediate points during navigation, landmarks,for instance. It can be clearly seen in FIG. 1, that simply by omittinginformation such as “addresses” and “polygons”, that is needed only fornavigation and not for the operation of vehicle control systems,forty-two percent less storage space is required.

In FIGS. 2 a) and b) the storage requirement is shown for individualareas for the same commercial digital roadmap as depicted in the piechart of FIG. 1. In the process “open spaces” (i.e., outside urban andvillage areas), are differentiated from “built-up areas”, FIG. 2 a)thereby shows the number of edges allotted to each area, while FIG. 2 b)shows the number of nodes allotted to each area. From this figure it canbe seen that by omitting geographic information about “built-up areas”(areas not suitable for a useful operation of most vehicle controlsystems), between sixty-seven and seventy-four percent less storagespace is required.

FIGS. 3 a) to c) in schematically depict preferred embodiments of theinvention. FIG. 3 a) shows a telematics platform, which comprisesvarious devices and calculators in a single packaged circuit. Suchdevices and calculators include additional positioning sensor (GPS), theinvention-related sensor arrangement including a 64 MB buffer, anadditional 8 MB buffer for intermediate storage of calculations, adevice for the communication between the vehicle and external units(GSM), and also for short range communications, (DSRC). This telematicsplatform is very versatile. Actually, positioning of the vehicle iscarried out by this device. With it the vehicle includes the telematicsplatform of a centrally based navigation and management system as wellas a road impact fee calculator. According to this invention itadditionally, provides geographic information to the vehicle.

In FIG. 3 b) the invention-related sensor arrangement comprising a 64 MBbuffer and the in-vehicle component of the centrally based navigationand management system are combined into a single unit, “FleetboardReduced™”. This unit includes the in-vehicle component of the centrallybased navigation and management system and is able to perform its owncalculations. However, it does not include any additional sensors, e.g.positioning sensors. These additional sensors are included in a separateunit to calculate road impact fees. The ETC unit comprises, in additionto its own calculator, an additional positioning sensor, GPS, anadditional 8 MB buffer for the interim calculation storage, thecommunication appliance between the vehicle and external units, GSM, andalso the appliance for short range communications DSRC. Apart from itsmain function, the independent calculation of road impact fees, the ETCunit by means of an information exchange provides information from theadditional sensors to the “Fleetboard Reduced™” unit as a “by-product”.According to the invention, The “Fleetboard Reduced™” unit providesvehicle control systems with geographic information.

In FIG. 3 c), the invention-related sensor arrangement comprising a 64MB buffer and a road impact fees calculator are combined into a singleETC unit. Therefore, in addition to the invention-related sensor deviceand the built-in road impact fees calculator, the ETC unit includes apositioning sensor, (GPS), an additional 8 MB buffer for the interimcalculations storage of the communication appliance between the vehicleand external units (QSM), and also the device for short rangecommunications, DSRC. The main function of the ETC unit is to calculateroad impact fees. For this purpose, it exchanges information with the“Fleetboard Reduced”™ unit. For example, the ETC unit receives a routeprovided by the centrally based navigation system via the “FleetboardReduced”™ unit. Here the ETC unit provides the system in the vehiclewith the information-related geographic information.

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

1.-17. (canceled)
 18. Sensor arrangement for a vehicle control system,said sensor arrangement, comprising: a buffer for geographicinformation, said buffer containing only geographic information suitableto describe at least one possible route of the vehicle; an inputinterface for selecting a subset of the geographic information stored inthe buffer, in response to at least one position-related parameterentered at the input interface; an output interface for outputting thesubset of the geographic information corresponding to the at least oneparameter values, whereby the output information is sent for furtherprocessing in the vehicle control system.
 19. The sensor arrangementaccording to of claim 18, wherein the buffer is overwritable.
 20. Thesensor arrangement according to claim 19, wherein the buffer comprises aflash ROM.
 21. The sensor arrangement according to claim 20, wherein atleast one of the input and output interfaces is connected to avehicle-based information network.
 22. The sensor arrangement accordingto claim 21, wherein the geographic information is at least partially orincrementally changeable.
 23. The sensor arrangement according to claim22, wherein change of the geographic information is performed by meansof a data transmission line connected to the buffer.
 24. The sensorarrangement according to claim 23, wherein one of a geographic positionof the vehicle, a geographic area based thereon, and a route sectionbased thereon, is entered as a parameter value at the input interface.25. The sensor arrangement according to claim 24, further comprising anEDP connection with a vehicle-based telematics platform.
 26. The sensorarrangement according to claim 25, further comprising an EDP connectionwith a vehicle-based road impact fees calculator.
 27. The sensorarrangement according to claim 26, further comprising an EDP connectionwith a navigation system.
 28. The sensor arrangement according to claim27, wherein the navigation system is centrally based.
 29. The sensorarrangement according to Claim 28, wherein the geographic information iscertified.
 30. The sensor arrangement according to claim 29, wherein anon straight parameter-based, partial section of a route is described insaid geographic data as a circular arc or a clothoid or a spline. 31.The sensor arrangement according to claim 18, wherein the geographicinformation describes at least one route of the vehicle.
 32. The sensorarrangement according to claim 31, wherein the vehicle is a commercialvehicle.
 33. The sensor arrangement according to claim 18, wherein thesensor arrangement comprises an intelligent sensor.
 34. The sensorarrangement according to Claim 33, wherein the geographic informationcomprises data describing only highways.